Concave Resurfacing Prosthesis

ABSTRACT

A glenoid component for use with a prosthetic humeral component for use in performing shoulder arthroplasty is provided. The glenoid component may be fitted at least partially into a cavity formed in the glenoid vault. The glenoid component includes a body having a stem portion for inserting at least partially into the cavity formed in the glenoid vault. The stem portion cooperates with the interior wall of the cavity formed in the glenoid vault. The body has a bearing portion for articulating cooperation with the prosthetic humeral component.

This application is a Continuation Application of U.S. application Ser.No. 12/005,205, filed Dec. 26, 2007, and entitled Tamp for ConcaveResurfacing Prosthesis, which is a Divisional Application of U.S.application Ser. No. 10/259,045, filed Sep. 27, 2002, and entitledConcave Resurfacing Prosthesis, now U.S. Pat. No. 7,329,284 issued Feb.12, 2008, the disclosures of each of the above-identified patentapplication and patent are hereby totally incorporated by reference intheir entirety.

TECHNICAL FIELD

The present invention relates generally to the field of orthopaedics,and more particularly, to an implant for use in arthroplasty.

BACKGROUND

The invention relates to implantable articles and methods formanufacturing such articles. More particularly the invention relates toa bone prosthesis and a process for manufacturing the same.

There are known to exist many designs for and methods for manufacturingimplantable articles, such as bone prostheses. Such bone prosthesesinclude components of artificial joints, such as elbows, hips, knees,and shoulders. An important consideration in the design and manufactureof virtually any implantable bone prosthesis is that the prosthesis hasadequate fixation when implanted within the body.

Earlier designs of implantable articles relied upon the use of cementssuch as polymethylmethacrylate (PMMA) to anchor the implant. The use ofsuch cements can have some advantages, such as providing a fixation thatdoes not develop free play or does not lead to erosion of the joiningbone faces postoperatively. However, the current trend is to use thecements to a lesser extent because of their tendency to lose adhesiveproperties over time and the possibility that the cement contributes towear debris within a joint.

Recently, implantable bone prostheses have been designed such that theyencourage the growth of hard bone tissue around the implant. Suchimplants are often implanted without cement and the bone grows aroundsurface irregularities for example, porous structures on the implant.

One such implantable prosthesis is a shoulder prosthesis. During thelifetime of a patient, it may be necessary to perform a total shoulderreplacement procedure on a patient as a result of, for example diseaseor trauma, for example, disease from osteoarthritis or rheumatoidarthritis.

In a total shoulder replacement procedure, a humeral component having ahead portion is utilized to replace the natural head portion of the armbone or humerus. The humeral component typically has an elongatedintermedullary stem which is utilized to secure the humeral component tothe patient's humerus. In such a total shoulder replacement procedure,the natural glenoid surface of the scapula is resurfaced or otherwisereplaced with a glenoid component that provides a bearing surface forthe head portion of the humeral component.

Glenoid components have been designed which include a number of plasticinserts coupled to metal backings. The metal backings are provided tosecure the plastic inserts to the glenoid surface of the scapula.

Unfortunately, for a variety of reasons, an implant, for example, ashoulder prosthesis, may occasionally need to be revised or have the oldimplant surgically removed and a new implant positioned where the priorimplant had been removed. Such a procedure is called a revision surgery.In total shoulder arthroplasty, failure of the glenoid component is theprimary cause for revision surgery. Primary failure modes are prematurewear of the articulating surface and loss of fixation.

When a failed glenoid component is removed, often the subcondylar plateis damaged or missing along with a large defect in the cancellous boneof the glenoid vault of the scapula.

Fixation of a revision glenoid component can be difficult to achievewith a resulting limited bone stock remaining on the glenoid vault ofthe scapula after the revision surgery has been performed. Often thesurgeon has to graft the glenoid defects and convert to ahemi-arthroplasty with a prosthetic humeral head articulating on theremaining natural glenoid articulating surface.

Attempts to provide for an adequate revision glenoid component forrevision surgery have met with less than optimal results. For example,current glenoid prosthesis designs include pegged, finned, interferencepeg and metal back screw type of glenoid prosthesis.

Referring now to FIG. 1, a healthy glenoid fossa 1 which is a portion ofthe scapula is shown. The healthy glenoid fossa 1 includes a glenoidarticulating surface 2 positioned on the subcondylar plate 3. Thehumeral head (not shown) of a healthy humerus rides against the glenoidarticulating surface.

Referring now to FIG. 2, a glenoid 4 is shown with posterior erosion 5on the glenoid articulating surface 6.

Prior art glenoid components have a generally concave shape with acylindrical member or peg extending outwardly in a direction opposed tothe concave articulating surface. When utilizing a standard glenoidprosthesis to repair a failed glenoid component, the posterior erosionrequires that the subcondylar plate be resected or reduced. Thesubcondylar plate needs to be reamed or resected away to correct theversion.

As shown in FIG. 3, the standard glenoid prosthesis 7 rests on onlycortical bone 8 along the periphery of the glenoid articulating surface.Not only is the support at the cortical bone areas 8 very limited, thesupport between the cortical bone maybe full of voids 9 which furtherreduce the ability of the standard glenoid prosthesis to be properlysupported.

Referring now to FIG. 4, a glenoid 10 is shown after removal of a failedglenoid component. The failed glenoid component resulted in a void inthe subcondylar plate and the underlying cancellous bone bed.

Referring now to FIG. 5, the failed glenoid of FIG. 4 is shown with astandard glenoid prosthesis 11 positioned over the remaining portions 12of the subcondylar plate. Again with the configuration of FIG. 5, thestandard glenoid prosthesis is only supported at the remaining portions12 of the subcondylar plate.

Referring now to FIGS. 6, 7, 8, and 9 various prior art attempts atproviding a satisfactory glenoid prosthesis are shown.

Referring first to FIGS. 6 and 7, prosthesis 13 and 17 are shown,respectively, for use with PMMA cement.

Referring first to FIG. 6, standard glenoid prosthesis 13 is shownpositioned over subcondylar plate 14. A series of pegs 15 are positionedthrough the subcondylar plate 14 into the cement 16 and cancellous bonebed. As can be seen, the prosthesis 13 requires an intact subcondylarplate 14 to properly support the prosthesis 13.

Referring now to FIGS. 7 and 7A, a finned glenoid prosthesis 17 isshown. The finned prosthesis 17 includes grooves 19 located on fin 18 ofthe prosthesis 17. The prosthesis 17 is also used with cement 20. As canbe seen, the finned prosthesis 17 also requires a subcondylar plate toproperly support the prosthesis 17.

Referring now to FIG. 8, an anchor peg prior art glenoid prosthesis 21is shown. The anchor peg prosthesis 21 includes cement pegs 22 as wellas anchor peg 24. The anchor peg 24 may be press fitted for boneingrowth while the cement pegs 22 are secured to the glenoidarticulating surface with cement 23. The anchor peg glenoid 21 alsodepends on the quality of the subcondylar plate.

Referring now to FIG. 9, yet another prior art glenoid prosthesis isshown as a metal backed glenoid with a screw 25. The glenoid prosthesis25 includes a metal backing 26 that supports a screw 27 that is fittedinto scapula 28. The metal backed with screw glenoid prosthesis 25, asshown in FIG. 9, also requires a well preserved subcondylar plate toproperly support the prosthesis 25.

As can be shown in FIGS. 1 through 9, in many cases the subcondylarplate defects and the underlying cancellous bone defects increase thedifficulty in achieving appropriate prosthesis fixation and support. Aneed, therefore, exists for a glenoid prosthesis for use in a patientwith a damaged or missing subcondylar plate.

SUMMARY

The present invention provides for a glenoid component and system thathas fixation to the inside walls of the glenoid vault and providescompressive load support from the remaining glenoid cortical rim. Thepresent invention provides for a glenoid resurfacing prosthesis withparticular application for treatment of posterior erosion and revisionapplications. For the resurfacing prosthesis of the present invention,the fixation and stabilization of the prosthetic component occurs insidethe glenoid vault.

According to the present invention, a glenoid component system may beprovided with multiple variable size variations to accommodatevariations in the human anatomy. Glenoid components consist of bothconcave lateral surfaces for articulation with a prosthetic humeral headand medial body configured for fixation against the inner wall of theglenoid vault. The rim of the concave articulating surface is configuredto rest against the remaining glenoid cortical rim.

The medial body configuration can be of a all polyethylene design forfixation against the inner wall of the glenoid vault with bone cement.It can also be designed with a metal porous coating backing and holes toaccept bone screws. The bone screws are used to provide initial fixationuntil bone ingrowth occurs on the porous surfaces of the metal backingmember. Also the prosthesis can be configured to replace lost bone whenposterior erosion of the glenoid surface has occurred.

According to one embodiment of the present invention, there is provideda glenoid component for use with a prosthetic humeral component for usein performing shoulder arthroplasty. The glenoid component may be fittedat least partially into a cavity formed in the glenoid vault. Theglenoid component includes a body having a stem portion for inserting atleast partially into the cavity formed in the glenoid vault. The stemportion cooperates with the interior wall of the cavity formed in theglenoid vault. The body has a bearing portion for articulatingcooperation with the prosthetic humeral component.

According to another embodiment of the present invention there isprovided a tamp for use in forming grafting material into a cavity inthe glenoid vault to prepare the vault for a glenoid component forperforming shoulder arthroplasty. The tamp includes a body and a formingportion extending in a first direction from the body. The formingportion has a surface shaped to receive the glenoid component.

According to a further embodiment of the present invention, there isprovided a method for providing shoulder arthroplasty. The methodincludes the steps of resecting a glenoid vault, providing a tool forforming a cavity in the glenoid vault, forming a cavity in the glenoidvault with the tool, providing a glenoid prosthetic component for atleast partially fitting into the cavity in the glenoid vault, andimplanting the glenoid prosthetic component in the cavity.

According to yet another embodiment of the present invention there isprovided a kit for use in performing shoulder arthroplasty. The kitincludes a tool for use in forming a cavity in the glenoid vault forperforming shoulder arthroplasty. The kit also includes a glenoidcomponent for use with a prosthetic humeral component.

The technical advantages of the present invention include the ability toprovide a glenoid prosthesis that does not depend upon the condition ofthe patient's subcondylar plate. For example, according to one aspect ofthe present invention, a glenoid prosthesis is provided whichsubstantially fills the glenoid vault and provides complete supportunder the articulating surface of the glenoid prosthesis. Thus, thepresent invention provides for improved support of the glenoidprosthesis independent of the condition of the subcondylar plate.

Another technical advantage of the present invention includes theability to provide for an effective glenoid prosthesis when the corticalwalls of the glenoid vault are severely damaged. For example, accordingto one aspect of the present invention, the prosthesis includes metalwalls that substitute for a portion of the cortical walls of the glenoidvault.

Yet another technical advantage of the present invention includes theability to provide for a glenoid prosthesis when the cancellous bone inthe glenoid vault has voids. For example, according to one aspect of thepresent invention, the glenoid vault is cleaned and removed ofcancellous bone. The glenoid vault then is filled with a combination ofbone graft and/or cement, and the prosthesis of the present inventionthat fills a substantial portion of the glenoid vault is implanted.Thus, the present invention provides for a glenoid prosthesis that issuitable to be used where the glenoid vault includes voids of cancellousbone.

Other technical advantages of the present invention will be readilyapparent to one skilled in the art from the following figures,descriptions and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference is now made to the following descriptiontaken in connection with the accompanying drawings, in which:

FIG. 1 is a top view partially in cross section of a healthy humanglenoid;

FIG. 2 is a top view partially in cross section of a human glenoid withposterior erosion;

FIG. 3 is a top view partially in cross section of a failed humanglenoid;

FIG. 4 is a top view partially in cross section of a prior art glenoidcomponent in position on an eroded human glenoid for use with aprosthetic humeral component for use in performing shoulder jointarthroplasty;

FIG. 5 is a top view partially in cross section of a prior art glenoidcomponent in position on a failed human glenoid for use with aprosthetic humeral component for use in performing shoulder jointarthroplasty;

FIG. 6 is a top view partially in cross section of a prior art cementedpegged glenoid component in position on a human glenoid for use with aprosthetic humeral component for use in performing shoulder jointarthroplasty;

FIG. 7 is a top view partially in cross section of a prior art cementedfinned glenoid component in position on a human glenoid for use with aprosthetic humeral component for use in performing shoulder jointarthroplasty;

FIG. 7A is a medial/lateral view partially in cross section of the FIG.7 finned glenoid component in position on a human glenoid;

FIG. 8 is a top view partially in cross section of a prior artnon-cemented anchor peg glenoid component in position on a human glenoidfor use with a prosthetic humeral component for use in performingshoulder joint arthroplasty;

FIG. 9 is a top view partially in cross section of a prior artnon-cemented metal backed glenoid component with screw in position on ahuman glenoid for use with a prosthetic humeral component for use inperforming shoulder joint arthroplasty;

FIG. 10 is a top view partially in cross section of a one-piece vaultfixed glenoid component for use with a prosthetic humeral component foruse in performing shoulder joint arthroplasty, the glenoid componentclosely conforming to the glenoid vault, in accordance with anembodiment of the present invention;

FIG. 11 is an end view of the glenoid component of FIG. 10;

FIG. 12 is a top view of another embodiment of the present invention inthe form of a shoulder prosthesis assembly using the a one-piece vaultfixed glenoid similar to that of FIG. 10;

FIG. 13 is a top view partially in cross section of a vault fixed(biological and/or cemented) glenoid component with optional screw foruse with a prosthetic humeral component for use in performing shoulderjoint arthroplasty, in accordance with another embodiment of the presentinvention;

FIG. 13A is a partial top view partially in cross section of the vaultfixed glenoid component of FIG. 13;

FIG. 14 is a medial/lateral view of the shoulder prosthesis assemblyusing the metal backed glenoid of FIG. 13;

FIG. 15 is a medial/lateral view of a glenoid vault showing mineralizedbone having been positioned in the glenoid cavity with the TAMP of FIGS.16 and 17;

FIG. 16 is a plan view of a tamp for use with the vault fixed(biological and/or cemented) glenoid component of FIGS. 13 and 14;

FIG. 17 is an end view of the tamp of FIG. 16;

FIG. 18 a top view partially in cross section of a metal backed vaultfixed (biological and/or cemented) glenoid component with screw for usewith a prosthetic humeral component for use in performing shoulder jointarthroplasty where there is posterior erosion, in accordance with afurther embodiment of the present invention;

FIG. 19 is an exploded perspective view of a shoulder prosthesisassembly in position in a humerus and a glenoid cavity using the FIG. 18metal backed vault fixed glenoid component with screw for use inperforming shoulder joint arthroplasty where there is posterior erosion;

FIG. 20 is a medial/lateral view of a shoulder prosthesis assembly usinga resilient one-piece glenoid for cementless application in accordancewith yet another embodiment of the present invention;

FIG. 21 is a partial perspective view of the glenoid component of FIG.20;

FIG. 22 is an exploded perspective view of the shoulder prosthesisassembly of FIG. 19;

FIG. 23 is a partial perspective view of the glenoid component withresilient glenoid vault contacting fingers in accordance with yetanother embodiment of the present invention;

FIG. 24 is a plan view partially in cross section of a umbrella typemechanically expandable vault fixed (cementless) glenoid component foruse with a prosthetic humeral component for use in performing shoulderjoint arthroplasty in accordance with yet another embodiment of thepresent invention;

FIG. 24A is a partial plan view of the expander of FIG. 24;

FIG. 25 is a plan view partially in cross section of a wedge typemechanically expandable vault fixed (cementless) glenoid component foruse with a prosthetic humeral component for use in performing shoulderjoint arthroplasty in accordance with a further embodiment of thepresent invention;

FIG. 26 is a partial top view of the expander of FIG. 25; and

FIG. 27 is a process flow chart for a method of performing shoulderjoint arthroplasty according to an embodiment of the present invention;

FIG. 28 is a top view of a template for preparing a resected surface forthe implantation of a metal backed glenoid;

FIG. 29 is a plan view partially in cross section of the template ofFIG. 28; and

FIG. 30 is a tool for use with the template of FIG. 28.

DETAILED DESCRIPTION

Embodiments of the present invention and the advantages thereof are bestunderstood by referring to the following descriptions and drawings,wherein like numerals are used for like and corresponding parts of thedrawings.

According to the present invention referring now to FIGS. 10 and 11, aglenoid component 100 for use with a prosthesis humeral component 102for use in shoulder arthroplasty is shown. The glenoid component 100 isfitted at least partially into a cavity 104 formed in the glenoid vault106 of the scapula 110. The glenoid component 100 includes a body 112having a stem portion 114 for inserting at least partially into thecavity 104 formed in the glenoid vault 106. The stem portion 114cooperates with the interior wall 116 of the cavity 104 formed in theglenoid vault 106. The body 112 also includes a bearing portion 120 forarticulating cooperation with the prosthetic humeral component 102.

The glenoid component 100 may be made of any suitable durable material.For example, the glenoid component 100 may be made of a plastic. Forexample, the glenoid component 100 may be made of a polyethylene. Oneparticular polyethylene that is well suited for a bearing portion is ahigh molecular weight polyethylene, for example ultra-high molecularweight polyethylene (UHMWPE). One such UHMWPE is sold by the assignee ofthe instant application or Marathon™ UHMWPE and more fully described inU.S. Pat. Nos. 6,228,900 and 6,281,264 to McKellop incorporated hereinin their entireties by reference.

The glenoid component 100 may have any suitable shape capable of fillinga substantial portion of the cavity 104. The glenoid cavity 104 may varysubstantially from patient to patient. Generally, however, the cavity104 has a generally inverted dome shape and has a generally ovalcross-section. Preferable the glenoid component 104 likewise has a ovaldomed shape to correspondence to that of the cavity 104. For example,referring to FIG. 10, the stem portion 114 of the glenoid component 100has a generally domed shape with a larger width WT adjacent the bearingportion 112 and a small diameter WB at the stem portion 112 opposed tothe bearing portion 120.

Referring to FIG. 11, the glenoid component 100 is preferably generallyoval with a major diameter MD that is substantially larger than theminor diameter ID. While the glenoid component 110 preferably has ashape similar to that of the cavity 104, it should be appreciated thatthe glenoid component 100 may completely fill the cavity 104 or thesomewhat smaller than the cavity 104.

As shown in FIGS. 10 and 11, the glenoid component 100 is in intimatecontact with the glenoid vault 106 to assist in the secure location ofthe glenoid component 100. Exact sizing of the glenoid component 100 tothe cavity 104 maybe somewhat difficult due to the unique anatomy ofevery individual. It should be appreciated that a series of glenoidcomponents 100 may be provided for accommodating the most common sizesof the glenoid cavity for various patients.

Referring now to FIG. 12, an alternative embodiment of the presentinvention is shown as glenoid component 200 for use with humeralcomponent 102. The glenoid component 200 of FIG. 12 is similar to theglenoid component 100 of FIGS. 10 and 11, except that the glenoidcomponent 200 includes a stem portion 214 which is sized relativelysmaller than the stem portion 114 of the glenoid component 110 of FIGS.10 and 11 so that cement 250 may be positioned between internal wall 116of the glenoid vault 106 and stem periphery 252 of the stem portion 214of the glenoid component 200. The cement 250 may be any suitable cementcapable of assisting and securing the glenoid component 200 to theglenoid vault 106. For example the cement may be polymethylmenthacrylate(PMMA).

The glenoid component 200 may as shown in FIG. 12 be an integralcomponent such as glenoid component 100 and may, for example be made ofa plastic for example high molecular weight polyethylene or ultra highmolecular weight polyethylene. The glenoid component 200 includes a body212 having a stem portion 214 and a bearing portion 220. The use of thecement 250 permits the use of a common glenoid component 200 for varyingsizes of the glenoid vault.

Referring now to FIGS. 13, 13A, and 14, another embodiment of thepresent invention is shown as glenoid component 300. Glenoid component300 is similar to the glenoid component 200 except that the glenoid 300further includes a support layer 354 surrounding a portion of body 312of the glenoid component 300.

The glenoid component 300 includes a body 312 having a stem portion 314and a bearing portion 320. The support layer 354 extends outwardly fromstem periphery 352 of the stem portion 314 of the body 312 of theglenoid component 300. As shown in FIG. 13, the support layer 354 mayinclude a lip 353 which extend outwardly from the distal end of thesupport layer 354. The lip 353 rests on cortical wall 355 and providessupport for the glenoid component 300. The support layer 354 may be madeof any suitable durable material and may be made as a metal compatiblewith the human anatomy, for example, a cobalt chromium alloy, astainless steel alloy or a titanium alloy.

Support layer periphery 360 of the support layer 354 may, as shown inFIG. 13, be in intimate contact with inner wall 116 of the glenoid vault106. The support layer periphery 360 may include a porous coating 362 toassist in the bone in growth of the glenoid component 300 to the glenoidvault 106.

The coating 362 may be any suitable porous coating and may for examplebe Porocoat®, a product of the assignee of the instant application andmore fully described in U.S. Pat. No. 3,855,638 to Pilliar herebyincorporated by reference in its entireties.

As shown in FIG. 13, the glenoid component 300 may further include afastener 364 in the form of, for example, a screw.

The screw 364 may be any screw capable of assisting and securing theglenoid component 300 to the glenoid vault 106. For example, the screw364 may be in the form of a cortical screw, for example, a corticalscrew available from DePuy Orthopaedics, Inc. the Assignee of theinstant application. One such cortical screw is DePuy Ace catalog number8150-36-030.

The screw 364 has a diameter SD of sufficient diameter to properlysecure the glenoid component 300 to the glenoid vault 106 and may, forexample, have a diameter SD of about two to five millimeters. The screw364 may have any suitable length capable of properly securing theglenoid component 300 to the glenoid vault 106 and reaching sufficientbone in the scapula 110 to properly secure the glenoid component 300.For example, the screw 364 may have a length of SL of from 10 to 60millimeters.

The screw 364 may be secured to the glenoid component 300 in anysuitable fashion and may, as shown in FIG. 13, be secured to the supportlayer 354 of the glenoid component 300. The support layer 354 mayinclude an opening 366 through which the screw 364 partially passes.

The support layer 354 may be secured to the body 312 in any suitablemanner For example, the support layer 354 may be bonded to the body 312.For example, the support layer 354 could be made of polyethylene andcompression molded to the body 312. Alternately the support layer 354may be glued to the body 312 by, for example, an adhesive.

Alternatively the support layer 354 may be mechanically interlocked tothe body 312. For example, the support layer 354 may include surfacefeatures, for example, ribs (not shown) or perhaps a porous coating tomechanically interlock the support layer 354 to the body 312.

Alternatively and as shown in FIGS. 13 and 13A, the glenoid component300 may include a locking feature 370. The locking feature 370 may haveany shape capable of mechanically locking the support layer 354 to thebody 312. For example, the support layer 354 may include a lip 372 thatforms a groove 374 in the support layer 354. The body 312 may include aprotrusion 376 that matingly fits with the groove 374 to secure the body312 and the support layer 354 to each other. It should be appreciatedthat the protrusion 376 may be in the form of separate spaced-apartdetents or may be in the form of a circular ring.

When installing the glenoid component 300, the support layer 354 isfirst placed in the glenoid vault 106 and the screw 364 is positionedthrough the opening 366 and engages the scapula 110. After the screw 364is fully inserted, the body 312 may be placed into the support layer 354with the protrusion 376 being snapped into the groove 374 of the supportlayer 354.

As shown in FIG. 13 when viewing the glenoid vault 106 from above, thesupport layer 354 may closely conform to the glenoid vault 106. Further,when viewing the glenoid component 300 and the glenoid vault 106 in themedial lateral view of FIG. 14, the glenoid vault 106 curves inwardly inthe proximal direction with a shape that could be described as that of awine glass.

During the revision shoulder arthroplasty surgery, the cancellous bonewithin the cavity 104 is generally removed and the glenoid cavity 104 iscleaned to the inner wall 116 of the glenoid vault 106. It is thusdesirable to support the glenoid component 300 between the support layer354 and the inner wall 116 of the glenoid vault 106. A material suitablefor supporting the glenoid component 300 is preferably positioned in theglenoid vault 106. Such a material is graft mineralized bone fragmentsthat are commercially available or created from the patient's availablebone.

Continuing to refer to FIG. 14, the cavity 104 between inner wall 116 ofglenoid vault 106 and body support layer surface 380 of the supportlayer 354 of the glenoid component 300 is preferably filled with amineralized bone graft material 382.

Referring now to FIG. 15, the glenoid vault 106 is shown with themineralized bone graft material 382 in position in the cavity 104. Themineralized bone graft material 382 is preferably positioned with anouter contour 384 that conforms to the body support layer surface 380 ofthe glenoid component 300.

Referring now to FIGS. 16 and 17, another embodiment of the presentinvention is shown as tamp 386. The tamp 386 is for use in forming thegrafting material 382 (see FIG. 15) into the cavity 104 of the glenoidvault 106 to prepare the vault 106 for the glenoid component 300 forperforming shoulder arthroplasty.

The tamp 386 includes a body 390. The body 390 may have any suitableshape and may as is shown in FIGS. 16 and 17 have a generallycylindrical elongated shape. The tamp 386 further includes a formingportion 392 extending in a first direction from the body 390. Theforming portion 392 includes a surface 394 of the forming portion 392that is shaped to receive the glenoid component 300 (see FIGS. 13 and14). Preferably, the outer surface 394 of the forming portion 392 has ashape that is substantially similar to that of the outer surface 380 ofthe glenoid component 300 (see FIG. 14).

As shown in FIGS. 16 and 17, the tamp 386 may further include a handle396 which may be located opposed to the forming portion 392. The handle396 may serve to provide a place to hold the tamp 386 when it is beingused to position and tamp the graft material 382. Further, the handle396 may include a surface 398 for striking the tamp 386 to properlysecure the graft material 382. The tamp 386 may further include a stop399 positioned between the body 390 and the forming portion 392. Thestop 399 may be used to limit the motion of the tamp 386 and to providefor an accurate shape of the graft material 382 by resting the stop 399against the glenoid vault 106.

While the forming portion 392 may have any suitable shape, the formingportion 392 preferably conforms to the shape of the glenoid component300. While the glenoid component 300 may be circular, preferably toconform to the shape of the glenoid vault 106, the glenoid component 300is generally oval. Therefore, as shown in FIGS. 16 and 17, the formingportion 392 has an outer periphery 394 that is generally oval.

The tamp 386 may be made of any suitable durable material and may, forexample, be made of a titanium alloy, a cobalt chromium metal alloy, ora stainless steel alloy. The tamp 386 may be integral or may be made ofvarious components which are mechanically interlocked to each other.

Referring now to FIGS. 18 and 19, another embodiment of the presentinvention is shown as glenoid component 400. Glenoid component 400 issimilar to glenoid component 300 of FIGS. 13 and 14 except that glenoidcomponent 400 is designed to accommodate those patients in whom at leasta portion of the glenoid vault 106 is damaged or missing.

Referring now to FIG. 19, the glenoid vault 106 of the scapula 110 isshown having a void 165 in the vault periphery 167 of the glenoid vault106. A purpose of the glenoid component 400 is to replace at least aportion of the void 165 in the vault periphery 167. The glenoidcomponent 400 thus includes a vault replacement portion 475.

The vault replacement portion 475 extends downwardly from bearingportion 420 of the glenoid component 400. The vault replacement portion475 extends from bearing portion periphery 421 of the bearing portion420 of the glenoid component 400. The outer surface 477 of the vaultreplacement portion 475 extends from the bearing portion periphery 421and is aligned with vault periphery 167 of the glenoid vault 106.

In order to provide a glenoid component 400 that is commerciallyavailable, the glenoid component 400 includes a vault replacementportion 475 that has a vault replacement portion edge periphery 479 thatis smaller and extends within edge periphery 169 of the void 165 in theglenoid vault 165. The glenoid component 400 includes the bearingportion 420 that is similar to the bearing portion 320 of the glenoidcomponent 300 of FIGS. 13 and 14. The bearing portion 420 mates with thehumeral head 132 of the humeral component 102.

The glenoid component 400 also includes a body 412 that is similar body312 of the glenoid component 300 of FIGS. 13 and 14. The body 412 alsoincludes a stem portion 414 that is similar to stem portion 314 of thebearing component 300 of FIGS. 13 and 14, except that the stem portion414 further includes the vault replacement portion 475.

To accommodate the space between the void 165 in the glenoid vault 106and the vault replacement portion 475, the gap 157 between the vaultreplacement portion 475 and the glenoid vault 106 may be filled with,for example, graft material 482 similar to the graft material 382 of theglenoid component 300 of FIGS. 13 and 14.

Referring again to FIG. 18, the glenoid component 400 includes, inaddition to the body 412, a support surface 454 similar to the supportlayer 354 of the glenoid component 300 of FIGS. 13 and 14, except thatthe support layer 454 does not extend into the vault replacement portion475 of the body 412.

The glenoid component 400 may further include a screw 464 similar to thescrew 364 of the glenoid component 300 of FIGS. 13 and 14. The screw 464may be secured to the support layer 454 by means of, for example, ascrew head 465 which mates with the support layer 454 of the glenoidcomponent 400. The screw 464 passes through opening 466 in the supportlayer 454. The screw 464 is similar to the screw 364 of the glenoidcomponent 300 of FIGS. 13 and 14.

The body 412 may be made of any suitable material and may for example bemade of materials similar to that of the body 312 of the glenoidcomponent 300 of FIGS. 13 and 14. The body 412 may be secured to thesupport layer 454 in any suitable method and may, for example, besecured in a method similar to that of the glenoid component 300 andmay, for example, include a locking feature 470 similar to the lockingfeature 370 of the glenoid component 300.

While the vault replacement portion 475 of the glenoid component 400 ofFIGS. 18 and 19 may be a portion of the body 412 and be made of, forexample, a plastic, it should be appreciated that the vault replacementportion 475 may be a part of the support layer 454.

Referring now to FIGS. 20, 21 and 22, another embodiment of the presentinvention is shown as glenoid component 500. Glenoid component 500 issimilar to glenoid component 100 of FIGS. 10 and 11 except that glenoidcomponent 500 includes a resilient integral portion 507 which isconformable to be positionable within the glenoid vault 106 and expandson being positioned in the glenoid vault 106 to conform to the innerwalls 116 of the glenoid vault 106.

As shown in FIG. 20, the glenoid component 500 includes a body 512,which body 512 includes a stem portion 514 and a bearing portion 520.The bearing portion 520 is similar to the bearing portion 120 of theglenoid component 100 of FIGS. 10 and 11. The stem portion 514 includesa resilient integral portion 507 that expands to conform to the innerwalls 116 of the glenoid vault 106. The resilient integral portion 507may, as shown in FIG. 20, be in the form of a lip 507.

Referring now to FIG. 22, the glenoid component 500 is shown positionedbetween the prosthetic humeral component 102 and the glenoid vault 106.The bearing portion 520 of the glenoid component 500 mates with head 132of the prosthetic humeral component 102. The lip 507 of the glenoidcomponent 500 is shown in solid in a relaxed position 511 and in phantomin a constrained position 513.

When in the constrained position 513, the lip 507 has a constraineddiameter CD that is equal to or smaller than the vault diameter VD ofthe glenoid vault 106. Therefore, the stem portion 514 of the glenoidcomponent 500 can be positioned in the glenoid cavity 104 of thescapular 110. Upon insertion into the glenoid cavity 104, the lip 507returns to the relaxed diameter RD that is larger than the vaultdiameter VD of the glenoid cavity 104. Thus, the glenoid component 500is constrained within the glenoid vault 106.

The glenoid component 500 may be made of any suitable durable materialand may, as shown in FIGS. 21 and 22 be integrally molded of a plastic.For example, the glenoid component 500 may be made of a polyethylene,for example ultra-high molecular weight polyethylene. It should beappreciated that the stem portion 514 may include one or more slit 521to permit the stem portion 514 to have greater flexibility to permit theexpansion and contraction of the lip 507 to fit within the glenoid vault106.

Referring now to FIG. 21, the lip 507 is shown in greater detail. Thelip 507 has a relaxed diameter RD that is larger than the stem diameterSD of the stem 514 of the glenoid component 500.

Referring now to FIG. 23, an alternate embodiment of the presentinvention is shown as glenoid component 600. Glenoid component 600 issimilar to glenoid component 500 of FIGS. 20, 21 and 22, except thatglenoid component 600 includes a plurality of fingers 607 which servethe purpose of the lip 507 of the glenoid component 500. The glenoidcomponent 600 thus includes a body 614 which includes a bearing portion620 similar to the bearing portion 520 of the glenoid component 500 ofFIGS. 20, 21 and 22, as well as a stem portion 614 which is differentthan the stem portion 514 of the glenoid component 500 of FIGS. 20, 21and 22 in that the stem portion 614 includes the fingers 607.

Under the present invention and referring now to FIG. 24, anotherembodiment of the present invention is shown as glenoid component 700.The glenoid component 700 is similar to the glenoid component 300 ofFIGS. 13 and 14 except that the stem component 714 is in the form of anexpander 740. The glenoid component 700 includes a body 712, whichincludes a stem portion 714 and a bearing portion 720.

The bearing portion 720 may be integral with the body 712 or, as shownin FIG. 24, the bearing component 720 may be a separate component. Ifthe body 712 and the bearing component 720 are made of a integralcomponent, the body 712 is preferably made of a plastic, for exampleultra-high molecular weight polyethylene. It should be appreciated,however, that the body 712 may likewise be made of a durable metalcompatible with the human body.

If the body 712 and the bearing component 720 are made of separablecomponents as shown in FIG. 24, the body 712 is preferably made of ametal. For example, the body 712 may be made of a cobalt chromium alloy,a titanium alloy, or a stainless steel alloy. The bearing component 720,if made of a separable component, is preferably made of a plastic, forexample an ultra-high molecular weight polyethylene.

A locking feature 770 that is similar to the locking feature 370 of theglenoid component 300 of FIGS. 13 and 14 may be used for securing thebearing portion 720 to the body 712. The expander 470 is operablyconnected to the body 712 through, for example, a opening 766 in thebody 712.

The expander 740 is positioned at least partially within the cavity 104of the glenoid vault 106. A portion of the expander 740 may be urgedagainst inner walls 116 of the glenoid vault 106. The expander 740 may,as shown in FIG. 24, include a screw 764 that is fitted through opening766 in the body 712. The screw 764 may be any commercially availablebone screw similar to bone screw 364 of the glenoid component 300 ofFIGS. 13 and 14. The screw 764 engages cortical bone in the scapula 110.

The screw 764 is threadably secured to a tube 768 at threaded end 772 ofthe tube 768. The tube 768 is in clearance with the screw 764 on bearingend 774 of the tube 768. Longitudinal slits 776 are formed in the tube768 and form staves 778 between the threaded end 772 and the bearing end774 see (FIG. 24A).

Referring again to FIG. 24, the staves 778 have crimped portions 780equidistant from the bearing end 774 and the threaded end 772. Thecrimped portions 780 separate upper stave portions 782 from lower staveportions 784. As the threaded end 772 is moved upwardly in the directionof arrow 786, the staves 778 are bent with the upper stave portion 782and the lower stave portions 784 forming an angle .alpha. there between.

When the glenoid component 700 is positioned in vault 106, the screw 764is rotated causing the screw 764 to engage the scapula 110 and causingthe threaded end 772 of the tube 768 to move in the direction of arrow786 causing the crimped sections 780 of the staves 778 to move in thedirection of arrows 788 toward inner walls 116 of the glenoid vault 106,thereby securing the glenoid component 700 to the glenoid vault 106.

The tube 768 may be made of any suitable durable material and may, forexample, be made of a flexible metal compatible with the human body, forexample a titanium alloy. It should be appreciated that the tube 768 maybe made of a stainless steel alloy or a cobalt chromium alloy.

Referring now to FIGS. 25 and 26, another embodiment of the presentinvention is shown as glenoid component 800. Glenoid component 800 issimilar to glenoid component 700 of FIG. 24. For example, the glenoidcomponent 800 includes a body 812 similar to the body 712 of the glenoidcomponent 700 of FIG. 24. Further, the glenoid component 800 includes abearing portion 820 similar to the bearing portion 720 of the glenoidcomponent 700 of FIG. 24. The glenoid component 800 also includes a stemportion 814. The stem portion 814 is similar to the stem portion 714 ofthe glenoid component 700 in that the stem portion 814 includes anexpander 840, similar to the stem portion 714 including an expander 740.

The expander 840 is somewhat different than the expander 740 of theglenoid component 700. The expander 840 includes a screw 864 similar tothe screw 764 of the glenoid component 700. The expander 840 alsoincludes a wedge-shaped nut 868. The wedge-shaped nut 868 has aclearance fit to the screw 864. The wedge-shaped nut 868 includes awedge-shaped outer periphery 870 that is threadably engaged with aspider 872.

The spider 872 includes a series of spaced apart bars 874 which includeouter edges 876 that engage inner walls 116 of the glenoid vault 106.The spider 872 further includes an inner band 878 that is threadablyengaged with the outer periphery 870 of the wedge-shaped nut 868.

As the screw 864 is rotated to engage the cortical bone of the scapula110, shoulder 179 of screw 864 engages top 869 of nut 869. Upon contactby the screw 864, the wedge-shaped nut 868 is advanced in the directionof arrow 880, causing the bars 874 to advance outwardly in the directionof arrow 882 until the outer periphery 876 of the bars 874 engage theinner walls 116 of the glenoid vault 106.

The wedge-shaped nut 868 and the spider 872 may be made of any suitabledurable material that is compatible with the human body. For example,the spider 872 and the wedge-shaped nut 868 may be made of a titaniumalloy, a cobalt chrome alloy, or a stainless steel alloy.

Referring now to FIG. 27, another embodiment of the present invention isshown as surgical procedure 900. The surgical procedure 900 includes afirst step 910 of resecting a glenoid vault. The procedure 900 furtherincludes a second step 920 of providing a tool for forming a cavity inthe glenoid vault. The surgical method 900 further includes a third step930 of forming a cavity in the glenoid vault with a tool. The method 900further includes a fourth step 940 providing a glenoid prostheticcomponent for at least partially fitting into the cavity in a glenoidvault. The method 900 further includes a fifth step 950 of implantingthe glenoid prosthetic component in the cavity.

Referring now to FIGS. 28 and 29, a template 1010 is shown for preparingthe edge 1020 of the cortical bone of the glenoid vault 106. Such atemplate is particularly useful in connection with the use of theglenoid component 400 of FIG. 18 to prepare edge 473 when a portion ofthe cortical wall has been lost. The template includes a pilot portion1030 which mates with the inner wall of the glenoid vault 106 and servesto position the template with respect to the vault 106. The template1010 also includes a guiding groove 1040 that guides a tool 1050 as itremoves bone from the edge 1020 of the glenoid vault 106 to provide asurface for proper support of the glenoid component. The tool 1050 mayfor example be translated along groove 1040 in the direction of arrow1060 from first position 1070 as shown in phantom to second position1080 as shown in solid and then to third position 1090 as shown inphantom.

The template 1010 may be made of any suitable durable material that maybe sterilized and may, for example, be made of a metal, for example,cobalt chromium alloy, a titanium alloy or a stainless steel.

Referring now to FIG. 30 the tool 1050 is shown in greater detail. Thetool 1050 may include a cutting surface 1100 for cutting the bone. Thetool 1050 may also include a stop 1110 for limiting the travel of thetool along its longitudinal axis. The tool 1050 may also include a shank1120 for connection with a power tool (not shown).

The tool 1050 may be made of any suitable durable material that may besterilized and may, for example, be made of a metal, for example, asteel alloy, a titanium alloy or a stainless steel. The cutting surface1100 may be made of a separate material that has improved wearproperties such as carbide or diamond.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions, andalterations can be made therein without departing from the spirit andscope of the present invention as defined by the appended claims.

1. A glenoid component for use with a prosthetic humeral component foruse in performing shoulder arthroplasty, said glenoid component to befitted at least partially into a cavity formed in the glenoid vault,said glenoid component comprising a body having a stem portion forinserting at least partially into the cavity formed in the glenoidvault, said stem portion cooperating with the interior wall of thecavity formed in the glenoid vault, said body having a bearing portionfor articulating cooperation with the prosthetic humeral component. 2.The glenoid component of claim 1, wherein said body comprises a plastic.3. The glenoid component of claim 2, wherein said body comprises a highmolecular weight polyethylene.
 4. The glenoid component of claim 1,wherein said body substantially fills the glenoid vault.
 5. The glenoidcomponent of claim 1, further comprising a support layer surrounding atleast a portion of said body.
 6. The glenoid component of claim 5,wherein said support layer comprises a metal.
 7. The glenoid componentof claim 1, further comprising a fastener extending from said body. 8.The glenoid component of claim 1, wherein said glenoid component isadapted to be secured to the glenoid with bone cement.
 9. The glenoidcomponent of claim 1, wherein said stem portion includes a resilient,integral portion thereof which is conformable to be positionable withinthe glenoid vault and expands upon being positioned in the glenoid vaultto conform to the inner walls of the glenoid vault.
 10. The glenoidcomponent of claim 1, wherein said stem portion comprising an expanderoperably connected to said body and positioned at least partially withinthe body cavity wherein a portion of said expander is urged against theinner walls of the glenoid vault.
 11. The glenoid component of claim 10,wherein said expander comprises: a screw; and a tube defining an axialslot thereon, said tube threadably connected to said screw, a portion ofsaid tube being adapted for selective intimate contact with the innerwall of the glenoid vault.
 12. The glenoid component of claim 10,wherein said expander comprises: a screw; and a member at leastpartially positioned in the body cavity, said member being threadablyconnected to said screw, said screw wedgingly threadably expanding saidmember into intimate contact with the inner wall of the glenoid vault.13. A tamp for use in forming grafting material into a cavity in theglenoid vault to prepare the vault for a glenoid component forperforming shoulder arthroplasty, said tamp comprising: a body; and aforming portion extending in a first direction from said body, saidforming portion including a surface thereof shaped to receive theglenoid component.
 14. The tool of claim 13, wherein the surface of saidforming portion has a shape substantially similar to a surface of theglenoid component.
 15. A method for providing shoulder arthroplastycomprising: resecting a glenoid vault; providing a tool for forming acavity in the glenoid vault; forming a cavity in the glenoid vault withthe tool; providing a glenoid prosthetic component for at leastpartially fitting into the cavity in the glenoid vault; and implantingthe glenoid prosthetic component in the cavity.
 16. The method of claim15, wherein the forming the cavity step comprises forming the cavitysuch that the cavity substantially fills the glenoid vault.
 17. A kitfor use in performing shoulder arthroplasty, said kit comprising: a toolfor use in forming a cavity in the glenoid vault for performing shoulderarthroplasty; and a glenoid component for use with a prosthetic humeralcomponent for use in performing shoulder arthroplasty.
 18. The kit ofclaim 17 further comprising a humeral stem for implantation into thehumerus.
 19. The kit of claim 17, wherein said glenoid component isadapted to be fitted at least partially into a cavity formed in theglenoid vault, said glenoid component comprising a body having a stemportion for inserting at least partially into the cavity formed in theglenoid vault, said stem portion cooperating with the interior wall ofthe cavity formed in the glenoid vault, said body having a bearingportion for articulating cooperation with the prosthetic humeralcomponent.
 20. The kit of claim 17 wherein said tool comprises: a body;a shank extending in a first direction from said body; and a cuttingedge extending from said body in a direction opposed to said shank, saidcutting edge adapted to form a cavity in the glenoid vault.